Monoamine oxidase (MAO), specifically MAO-B. Pargyline is a monoamine oxidase inhibitor (MAOI) that targets MAO-B. MAO is a mitochondrial outer membrane flavoenzyme that catalyzes the oxidative deamination of monoamines, including neurotransmitters such as dopamine, norepinephrine, and serotonin. By inhibiting MAO, Pargyline increases the levels of these neurotransmitters in the brain. Pargyline is a mechanism-based inhibitor that begins with an initial reversible interaction (Ki = 4-5 μM) and proceeds to irreversible loss of enzyme activity. The compound is an irreversible selective MAO-B inhibitor. By inhibiting MAO-B, Pargyline increases dopamine levels in the brain, which is beneficial in Parkinson's disease. Pargyline is used to treat moderate to severe hypertension and as an antiparkinson agent.

Treatment with pargyline (0.5-2 mM; 24-120 hours; LNCaP-LN3 cells) inhibits prostate cancer cell proliferation in a dose- and time-dependent manner [2]. In a dose-dependent manner, pargyline (0.5-2 mM; 24-48 hours; LNCaP-LN3 cells) treatment decreases the S phase and increases the G1 phase in cells [2]. Treatment of LNCaP-LN3 cells with 0.5 mM of pargyline for 24 hours increases apoptosis [2]. Treatment with pargyline (2 mM; 48 hours; LNCaP-LN3 cells) causes a rise in cytochrome c and a fall in caspase-3 in cells, but it has no effect on BCL-2 expression [2].
Pargyline demonstrates MAO inhibitory activity in vitro. The compound is a mechanism-based inhibitor that begins with an initial reversible interaction (Ki = 4-5 μM) and proceeds to irreversible loss of enzyme activity. Pargyline is an irreversible selective MAO-B inhibitor. The compound's inhibitory activity has been characterized in enzymatic assays measuring MAO activity. By inhibiting MAO, Pargyline increases the levels of monoamine neurotransmitters, which underlies its antihypertensive and antiparkinsonian effects. Pargyline's selectivity for MAO-B over MAO-A contributes to its specificity and reduced side effects.

When pargyline (10 mg/kg; intravenously) is administered to unanesthetized adult spontaneously hypertensive rats (SHR) in normotensive rats, the treatment causes a moderate (about 20 mm Hg) but long-lasting (48 h) drop in systolic blood pressure. Alternatively [3]. Arterial pressure decreases when 200 μg of icv pargyline is injected directly into the brain. The build-up of norepinephrine at inhibitory α-adrenergic receptors in the brain appears to be the cause of pargylline's hypotensive impact in SHR [3].
Pargyline is used clinically as an antihypertensive agent and as an antiparkinson agent. The compound is an irreversible selective MAO-B inhibitor that increases dopamine levels in the brain, which is beneficial in Parkinson's disease. Pargyline has been used to treat moderate to severe hypertension. The compound's antihypertensive effects are attributed to its inhibition of MAO, leading to altered catecholamine metabolism. Pargyline's use has declined with the availability of newer antihypertensive agents, but it remains used in Parkinson's disease research. Pargyline is for research use only and is not for human therapeutic use.

MAO enzyme activity assays are performed using recombinant MAO-A or MAO-B enzymes or tissue homogenates (e.g., liver mitochondria). The enzyme is incubated with a substrate (e.g., kynuramine, tyramine, or serotonin) in assay buffer (50 mM phosphate buffer pH 7.4) at 37°C for 30-60 minutes. The reaction product is quantified by spectrophotometry or fluorometry. Pargyline is serially diluted in DMSO and added to the reaction mixture to determine IC50 and Ki values. The Ki for Pargyline is 4-5 μM. Each concentration is tested in duplicate, and IC50 values are calculated by non-linear regression analysis. Appropriate positive controls (e.g., clorgyline for MAO-A, selegiline for MAO-B) and vehicle controls are included to validate the assay.

Cell Proliferation Assay[2]
Cell Types: LNCaP-LN3 Cell
Tested Concentrations: 0.5 mM, 1 mM, 1.5 mM or 2 mM
Incubation Duration: 24 hrs (hours), 48 hrs (hours), 72 hrs (hours), 96 hrs (hours) or 120 hrs (hours)
Experimental Results: Inhibition of proliferation of prostate cancer cells in a time- and dose-dependent manner.

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Cell cycle analysis [2]
Cell Types: LNCaP-LN3 Cell
Tested Concentrations: 0.5 mM, 2 mM
Incubation Duration: 24 hrs (hours), 48 hrs (hours)
Experimental Results: The proportion of cells in S phase diminished and the proportion of G1 phase increased.

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Apoptosis analysis[2]
Cell Types: LNCaP-LN3 Cell
Tested Concentrations: 0.5 mM
Incubation Duration: 24 hrs (hours)
Experimental Results: Increased apoptotic cells.

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Western Blot Analysis[2]
Cell Types: LNCaP-LN3 Cell
Tested Concentrations: 2 mM
Incubation Duration: 48 hrs (hours)
Experimental Results: Induction of increased cytochrome c and diminished caspase-3.
Cellular MAO inhibition is evaluated in neuronal cell lines (e.g., SH-SY5Y) or other cell types expressing MAO. Cells are cultured in appropriate media at 37°C with 5% CO₂ and treated with Pargyline at various concentrations for 24-72 hours. MAO activity in cell lysates is assessed using substrate-based assays. Monoamine levels (e.g., dopamine, norepinephrine) are measured by HPLC or ELISA. Cell viability is assessed using MTT or LDH assays. Each experiment includes vehicle controls (DMSO) and appropriate positive controls (e.g., selegiline).

In vivo efficacy of Pargyline is evaluated in animal models of hypertension and Parkinson's disease. The compound is administered orally or intraperitoneally at doses determined by preclinical studies. Blood pressure is measured by telemetry or tail-cuff methods. In Parkinson's disease models, motor function is assessed using the rotarod test, open field test, and other behavioral tests. Dopamine levels in the brain are measured by HPLC. Sample sizes typically range from 6-10 animals per group.

Molecular Weight: 159.23. Formula: C11H13N. CAS No.: 555-57-7. IUPAC Name: N-methyl-N-2-propynylbenzenemethanamine. Synonyms: Pargyline; Eutonyl; N-benzyl-N-methyl-2-propynylamine. Appearance: Crystals. Melting Point: 154-155°C. Solubility: Readily soluble in water; aqueous solutions are unstable. Storage: Typically at room temperature. Pargyline is an irreversible selective MAO-B inhibitor used as an antihypertensive and antiparkinson agent.

Pargyline has significant toxicity concerns. As a monoamine oxidase inhibitor, it can cause hypertensive crisis when combined with tyramine-containing foods or other sympathomimetic drugs. Common adverse effects may include orthostatic hypotension, dizziness, and dry mouth. Standard toxicity studies have been conducted for its approved uses. The compound is for research use only and is not for human therapeutic use.

[1]. The nature of the inhibition of rat liver monoamine oxidase types A and B by the acetylenic inhibitors clorgyline, l-deprenyl and pargyline. Biochem Pharmacol. 1982 Nov 15;31(22):3555-61.

[2]. Effects of the monoamine oxidase inhibitors pargyline and tranylcypromine on cellular proliferation in human prostate cancer cells. Oncol Rep. 2013 Oct;30(4):1587-92.

[3]. Central mediation of the antihypertensive effect of pargyline in spontaneously hypertensive rats. Eur J Pharmacol. 1979 Jul 15;57(1):21-7.

Pargiline is an aromatic amine. Pargiline is a monoamine oxidase inhibitor with antihypertensive effects. Pargiline is a monoamine oxidase (MAO) inhibitor with antidepressant activity. Pargiline selectively inhibits monoamine oxidase type B (MAO B), an enzyme that catalyzes the oxidative deamination and inactivation of certain catecholamines (such as norepinephrine and dopamine) in presynaptic nerve endings. By inhibiting the metabolism of these biogenic amines in the brain, pargiline increases their concentration and enhances their binding to postsynaptic receptors. Enhanced receptor stimulation may lead to downregulation of central receptors, which may explain pargiline's antidepressant effect. A monoamine oxidase inhibitor with antihypertensive effects. See also: methylchlorothiazide; pargiline hydrochloride (note moved to).

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Drug Indications
For the treatment of moderate to severe hypertension.

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Mechanism of Action
Monoamine oxidase inhibitors (MAOIs) work by inhibiting the activity of monoamine oxidase, thereby preventing the breakdown of monoamine neurotransmitters and increasing their bioavailability. There are two isoenzymes of monoamine oxidase, MAO-A and MAO-B. MAO-A preferentially deaminates serotonin, melatonin, adrenaline, and noradrenaline. MAO-B preferentially deaminates phenylethylamine and trace amines. Pargiline works by inhibiting the metabolism of catecholamines and tyramine in presynaptic nerve endings. Catecholamines cause general physiological changes, preparing the body for physical activity (fight-or-flight response). Some typical effects include increased heart rate, blood pressure, blood glucose levels, and a generalized response of the sympathetic nervous system.
Pargyline is also known as Eutonyl and N-benzyl-N-methyl-2-propynylamine. Its IUPAC name is N-methyl-N-2-propynylbenzenemethanamine. Pargyline is a monoamine oxidase inhibitor (MAOI) that targets MAO-B. It is a mechanism-based inhibitor that begins with an initial reversible interaction (Ki = 4-5 μM) and proceeds to irreversible loss of enzyme activity. Pargyline is used to treat moderate to severe hypertension and as an antiparkinson agent. Regulatory approvals exist in some countries but use has declined. Pargyline is for research use only.

C11H13N

159.23

159.105

555-57-7

Pargyline hydrochloride;306-07-0

4688

Colorless to light yellow liquid

0.94

86-88ºC(4 torr)

156 - 160ºC

83ºC

n20/D 1.522(lit.)

1.751

0

1

3

12

159

0

N(C([H])([H])[H])(C([H])([H])C#C[H])C([H])([H])C1C([H])=C([H])C([H])=C([H])C=1[H]

DPWPWRLQFGFJFI-UHFFFAOYSA-N

InChI=1S/C11H13N/c1-3-9-12(2)10-11-7-5-4-6-8-11/h1,4-8H,9-10H2,2H3

N-benzyl-N-methylprop-2-yn-1-amine

Eudatin; Pargyline

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~100 mg/mL (~628.02 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (15.70 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (15.70 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (15.70 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)